Water-cooled lamp



M 9 L, J. BUTTOLPH WATER COOLED LAMP Filed. July 5, I924 K0 peratures inthe lamp are maintained.

Patented May 24, 1927.

UNITED STATES PATENT OFFICE.

LEROY J. BUTTOLPH, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO COOPER HEWITTELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A CORPORATION OF NEW JERSEY.

WATER-COOLED LAMP.

Application filed July 5,

The present invention relates to electric light radiating apparatususeful in the arts generally and particularly in the therapeutic artwhere diseases are treated by means of 5 radiations from a light sourcegiving off ultra violet rays, and has for its object to provide suchapparatus which can be manipm lated readily by hand by the operator.

l have discovered, when operating a quartz lamp or burner having a solidanode and a liquid cathode therein and an arc path of one or two incheson commercial circuits that it is impossible to maintain such a smallsized lamp in etficient operation on commercial circuits without the useof external heat radiating devices. As is generally known in the arttheanode and cathode should be I kept at considerably lower temperaturethan the arc path and especially the cathode. On

the other hand the arc path and the mercury vapor thereof is required tobe kept at a characteristic operating temperature in order to maintainthe proper resistance and. pressure of the vapor which serves as the arcpath.

A ccordingly, in my new invention, I provide the lamp with apparatus forconducting heat therefrom which functions to maintain the tcm 'ieratureof the radiant current stream between the electrodes of the lampat thedesired operating temperature for giving the maximum amount ofv light.in those cases where illumination is desired and the maximum quantity ofultra-violet light radiations where said radiations are desired.

'ThiS apparatus functions to maintain the electrodes of the lamp atproper temperatures which functioning as a matter of fact is an adjunctof keeping the are path at its proper operating temperature. In thisheat conducting apparatus are (1) a jacket of material which is a goodconductor of heat such as a metal, and (2) a poor heat conducting mediumsuch as Bakelite. cement, as

bestos, metal or alloy, having direct contact with both the lamp walland the jacket wall and having such a suitable proportion of the heatgenerated in the lamp therefrom that the proper operating temperature ortem- The area, extent, and position of contact of the said medium withthe lamp are governed to suit the operating conditions of the lamp. Itcan be extended substantially throughout the length of the lamp, or itmay be limited 1924. Serial No. 724,343.

to points near or at the electrodes of the lamp, or limited to an areaabout one of them, as, for instance, about the cathode chamber. In thisheat conducting apparatus the said jacket is thermally connected withmeans for dissipating heat substantial ly as fast as it is conducted toit from the lamp. such dissipating means being, for example, a watercell such as I use in an embodiment fully described below and shown inthe drawings accompanying this application. The said medium between thejacket and the lamp is of a material of lesser heat conductivity thanthat of the jacket whereby obtained the result of retaining sufficientof the heatgenerated in thelamp to keep the arc path at its properoperating temperature and of dissipating such quantities-as are inexcess of such requirements. So, as in the example of the water cellcited, the heat dissipation rate of the exterior cooling means being ofa given capacity and greater than the quantity generated in the lamp thesaid medium will operate.to conduct heat from the lamp tomaintain thelamp at its proper operating temperature and mternal vapor pressurebetween certain limits and well between the normal fluctuations of enerdelivered by commercial electrical circuits, or by such circuits whichare provided with auxiliary regulating. devices. The cooling capacity ofthe external dissipating means of course can be varied and set to suitthe particular conditions under which the lamp is to work by varying inthis case the rate of water flow through the water cell. In thepreferred embodiment of my lamp I employ said medium between the lampand jacket in the form of a ring about the cathode chamber thereof. Thejacket is formed 'to extend substantially the length of the lamp toreceive and conduct heat passed to it by radiation and convection fromthe body of the lamp. and to cooperate with said intermediate medium inits temperature controlling function.

I find that in supplying a lamp or burner with its customary casing andso on that varying'inanufacturing conditions result in conditions notuniform in the various casings resulting in difi'erent inherent heatconducting and dissipating characteristics and as implied abore I selectsaid heat conducting medium from such materials as Bakelite, cement,asbestos, metal, or an alloy to suit the operating conditions of thelamp and also in accordance with such inherent heat dissipatingcharacteristic of the lamp casing.

As an auxiliary means for conducting heat from the lamp and as readilychangeable means for controlling the rate of heat conducted fromthe lampI use flexible spring fingers contacting thermally with heat dissipatingmeans and provided with means for causing their contact with the lamp orfor removing them from contact therewith entirely, and also. forcarrying the area of their contact therewith which are fully describedbelow and shown in the drawings. Under certain conditions of theoperation of the lamp and with the necessary contact area of the fingerswith the lamp should it be desired the fingers alone can be used toconduct the heat from the lamp to suitable heat dissipating means.

I illustrate different forms of my invention in the accompanyingdrawings in which,

Fig. 1, is a vertical section of my artificially cooled hand lampshowing the heat conducting medium contacting with the greater portionof the outside surface of the lamp and having thermal contact throughoutthe greater part of the outside surface of said medium and thermalcontact through a water cell and also showing flexible fingers incontact with one part of the lamp.

Fig. 2, is a section view along line 22 of Fig. 1.

Fig. 3, is a section view along line 33 of Fig. 2.

Fig. 4, is a section view along line 44 and through Fig. 1 and shows inplan the details of the flexible contacting fingers and means for movingthem into and out of contact with the lamp and for varying the areas ofsaid contact.

Fig. 5, is a vertical elevation of a. lamp with the conducting mediumthereof formed in a ring about the cathode and a ring about the anode,the lamp being indicated by dotted lines.

Fig. 6, is a vertical elevation of a lamp with a jacket thereabout and aring of heat conducting material about the cathode of the lamp betweenthe jacket and the lamp.

Referring to the drawings the lamp 1 is surrounded throughout thegreater portion of its length by heat conducting medium 2 which is ofmaterial such as cement, Bakelite or a low melting alloy and which has alight conducting opening therethrough between its extremities. The lampis surrounded longitudinally by a' closure comprising the water cell 4and the casing 7 extending between the lateral extremities of the watercell and around the lamp and extending upwardly from the top and bottomof the water cell. The caps 16 and 17- at the top and bottom of thecasing complete the closure for the lamp. The electrical conductors 29and 30 passing through the easing 7 and insulated therethrough in asuitable manner serve to connect a suitable source of electric currentto the lamp through the conductors 26 and 27 which also serve to 7 vanesor fins 14 which also serve as a thermal contact between the jacket 3and water cell 4. These fins 14 extend substantially the length ofjacket 3 and are formed near the light conducting opening of jacket 3into a reflector and enlarged light conducting passageway as shown at 15in Fig. 2. At the point of juncture of enlargements 15 of vanes 14 withthe inner wall 9 of the water cell 4 is mounted in said wall 9 a lens 6which for use in the application of ultra violet light is made of silicaor some other material transparent to ultra violet light. Registeringwith lens 6 and said openings in jacket 3 and medium 2 is a lens 5mounted in the front wall 8 of water cell 4 and which is of similarmaterial to that of lens 6. These lenses have water tight seals betweenthem and the walls in which they are respectively mounted. Through thehandle 12 which is fixed to the back of easing 7 are liquid conductingpipes 31 and 32 which serve for connection with a water supply andexhaust. Said pipes 31 and 32 connect through pipes 10 and 11respectively to the upper part of the water cell 4 on either side of thepartition 13 which extends from the top of water cell 4 to the lenses inthe front and back walls thereof and which serve to distribute the waterthrough said cell and to insure proper cooling circulation therethrough.On wall 9 at the lower part of water cell 4 are fixed as by soldering.brazing, welding. belting and so on the flexible fingers 22. 23. 24. and25 which are so fixed at a point intermediate of their lengths and havetheir ends bent from wall 9 toward that portion oflamp l nearest them.These fingers are of spring material and are formed to tend to springout of contact or into contact with said lamp 1. The bolt 18 which has aleft hand screw at one end and a right hand screw at its other end andthreaded through the fingers serves to move said fingers into and out ofcontact with the, lamp, the right hand screw and the left hand screwcooperating to move the fingers on one side of the lamp cooperativelywith a similar movement of the fingers on the other side of Hit culatedfrom the source and to the exhaust through the pipes 31 and 32 andthereby through the water cell 4. With the cooling liquid incirculation, the lamp is started into operation by tilting the outfit sothat the mercury of the lamp bridges the gap between the electrodesthereof and then breaks the connection thus established whereupon thearc is formed between said electrodes. At the instant of startingbecause'of the low temperature in the lamp the voltage drop across it islow andis controlled bya stabilizing resistance in the auxiliaries usualto said lamps and not here shown. This initial current is necessarilyhigh and the mercury of the lamp heats up rapidly raising the vaporpressure of the mercury in the lamp and at the same time raising thearovoltage. This process continues until such time as the heat energy inthe lamp establishes equilibrium with the cooling members about thelamp. This equilibrium temperature is determined by the conductivity ofmedium 2,

Y (and said flexible fingers, when used, conduct heat through theirrespective thermal contacts to the water cell 4.) It is thus obviousthat the volt-ampere characteristic of the lamp is controlled by thiscontrol of heat equilibrium through such conduction by means of medium 2(and fingers 22 to 25) since the volt-ampere characteristic of-the lampitself is dependent primarily on the pressure of the mercury vapor inthe lamp. It follows from the foregoing then that the operation of theoutfit for any given set of conditions may be controlled and varied byvarying the electrical regulating devices in the auxiliary mechanism ofthe lamp, but it is preferred for any given setting. of the lampand itscontrol mechanism to vary the volt-ampere characteristic of the lamp byvarying the rate of cooling as set forth above.

-tween the lamp 1 and jacket 3 is formed principally about the cathodechamber 34 of lamp 1; the jacket 3 extends about the lamp substantiallythrough its length.

Fig. 5 shows a lamp 1- having the medium forme'l in two parts as onering 2" about the anode of the lamp and the other ring 2 about thecathode chamber. Both these rings are shown as being tapered to fit theinterior of the jacket 3. v

I claim as my invention: 1. In a water cooled lamp, in combination, alamp holding tube, a water, cell. heat conducting means betweensaid tubeand said cell, a light passageway between the ends of said tube andlight shielding means adjacent the ends of said tube.

2. In a water cooled lamp, in combination,

'a lamp enclosing tube therefor extending substantially the lengththereof, a heat conducting medium within said tube contacting with boththe tube and the lamp substantially throughout their contiguoussurfaces, said tube and medium having registering light conductingpassageways.

I 3. In a water cooled lamp. in combination, a lamp holding tube, awater cell in thermal contact therewith, means for circulating waterthrpugh said cell, said tube and cell' having registering lightconducting passageways. a casing extending between the sides of saidwater cell and enclosing said tube.

4. In a water cooled lamp, in combination, a lamp holding tube, a watercell in thermal contact therewith. means for circulating water throughsaid cell. said tube and cell having registering light conductingpassageways, a casing extending between the sides of said water cell andaround said tube, and caps completing a closure with said water cell andsaid casing.

5. In a water cooled lamp, in combination, a lamp holding tube, a watercell in thermal contact therewith, means for circulating water throughsaid cell, said tube and cell having registering light conductingpassageways, a casing extending between the sides of said water cell andaround said tube. and caps completing a closure with said water cell andsaid casing, a lamp in said tube and electrical conductors for said lamppassing through said closure.

6. In a water cooled lamp, in combination. a lamp holding tube, a watercell in thermal contact with said 'tube, a pair of lenses mounted inopenings in opposite Walls of said water cell and registering with saidtube aperture. a casing extending between the limits of said cell andabout said tube,

caps completing a closure with said casing and cell for said tube, awater conducting passageway to and from said water cell, an electriclamp in said tube and conductors therefor passing through said closure.

7. In combination, with an electric lamp a set of fingers of thermalconductive material, and means for moving said fingers into and out ofcontact with said lamp and for varying the pressure of said fingers onthe lamp.

8. In combination, with an electric lamp, a set of fingers of thermalconductive material, and means for moving said fingers successively intoand out of contact with said lamp and for varying the pressure of saidfingers on the lamp.

9. In combination, with an electric lamp,

' a set of fingers of thermal conductive material, and means for movingsaid fingers successively in pairs into and out of contact with saidlamp and for varying the pressure of said fingers on the lamp.

10. In a water cooled lamp, in combination, a lamp holding tube, a Watercell in thermal contact with said tube, a pair of lenses mounted inopenings in opposite walls of said water cell and registering with saidtube aperture, a casing extending between the limits of said cell andabout said tube, caps completing a closure with said casing and cell forsaid tube, a water conducting passageway to and from said water cell, anelectric lamp in said tube and conductors therefor passing through saidclosure, and a pair of fingers of thermal conductive material in thermalcontact with said water cell, and means for moving said fingers into andout of contact with said lamp and for varying the area with said lamp.

11. In a water cooled lamp, in combination, a lamp, :1 jacket thereaboutand a heat dium having registering light conducting openingstherethrough.

12. In a water cooled lamp, in combination, a lamp enclosing tubetherefor extending substantially the length thereof, a heat conductingmedium within said tube contacting with both the tube and the lamp, saidtube and medium having registering light conducting passageways.

13. In a water cooled lamp, in combination, a lamp enclosing tubetherefor extending substantially the length thereof, a heat conductingmedium within said tube contacting with both the tube and the lamp attheir contiguous surfaces about the electrodes of the lamp, said tubehaving a light conducting passageway through the wall thereof.

14. In a water cooled casing having a mercury vapor lamp, incombination. a lamp enclosing tube having a light conducting passagewaythrough its wall therefor extending substantially the length thereof, aheat conducting medium within said tube contacting with both the tubeand lamp at their contiguous surfaces about the cathode chamber of saidlamp.

15. In a water cooled lamp, in combination, a lamp, a lamp enclosingtube having a light passageway through the wall thereof, and a heatconducting medium within said tube of a material having a lesser heatconductivity than that of said tube. said medium contacting with saidtube and said lamp.

Signed at Hoboken, in the county of Hudson and State of New Yersey, this3rd day of July, A. D. 1924.

LEROY J. BUTTOLPH.

